@import url("https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&display=swap");

/* ===== BASE STYLES ===== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --bg-primary: #f8fafc;
  --bg-secondary: #ffffff;
  --text-primary: #1e293b;
  --text-secondary: #64748b;
  --accent: #3b82f6;
  --accent-hover: #2563eb;
  --gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  --glass-bg: rgba(255, 255, 255, 0.7);
  --glass-border: rgba(255, 255, 255, 0.18);
  --shadow: 0 8px 32px 0 rgba(31, 38, 135, 0.15);
}

[data-theme="dark"] {
  --bg-primary: #0f172a;
  --bg-secondary: #1e293b;
  --text-primary: #f1f5f9;
  --text-secondary: #94a3b8;
  --glass-bg: rgba(30, 41, 59, 0.7);
  --glass-border: rgba(255, 255, 255, 0.1);
  --shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.37);
}

body {
  font-family: "Inter", sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  transition: all 0.3s ease;
  overflow-x: hidden;
}

html {
  scroll-behavior: smooth;
}

/* ===== ANIMATED BACKGROUND ===== */
body::before {
  content: "";
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: var(--gradient);
  opacity: 0.05;
  z-index: -1;
  animation: gradientShift 15s ease infinite;
}

@keyframes gradientShift {
  0%,
  100% {
    transform: translateY(0) scale(1);
  }
  50% {
    transform: translateY(-20px) scale(1.05);
  }
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ===== NAVIGATION ===== */
nav {
  position: fixed;
  top: 0;
  width: 100%;
  background: var(--glass-bg);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--glass-border);
  z-index: 1000;
  padding: 1rem 0;
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-size: 1.5rem;
  font-weight: 700;
  background: var(--gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.nav-links {
  display: flex;
  gap: 2rem;
  list-style: none;
}

.nav-links a {
  color: var(--text-primary);
  text-decoration: none;
  font-weight: 500;
  transition: color 0.3s ease;
  position: relative;
}

.nav-links a::after {
  content: "";
  position: absolute;
  bottom: -5px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--accent);
  transition: width 0.3s ease;
}

.nav-links a:hover::after {
  width: 100%;
}

.theme-toggle {
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  padding: 0.5rem 1rem;
  border-radius: 50px;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  transition: all 0.3s ease;
}

.theme-toggle:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow);
}

.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  color: var(--text-primary);
}

/* ===== CONTAINER ===== */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 6rem 2rem 2rem;
}

/* ===== HERO SECTION ===== */
.hero {
  min-height: 90vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  position: relative;
}

.hero-content {
  background: var(--glass-bg);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-radius: 30px;
  border: 1px solid var(--glass-border);
  padding: 3rem;
  box-shadow: var(--shadow);
  max-width: 800px;
  animation: fadeInUp 1s ease;
}

.profile-image {
  width: 288px;
  height: 288px;
  border-radius: 50%;
  margin: 0 auto 2rem;
  border: 5px solid var(--glass-border);
  box-shadow: var(--shadow);
  object-fit: cover;
}

.hero h1 {
  font-size: 3rem;
  margin-bottom: 0.5rem;
  background: var(--gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero .subtitle {
  font-size: 1.5rem;
  color: var(--text-secondary);
  margin-bottom: 1rem;
}

.hero .description {
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto 2rem;
  line-height: 1.8;
}

.social-links {
  display: flex;
  gap: 1rem;
  justify-content: center;
  margin-top: 2rem;
}

.social-link {
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  padding: 0.75rem 1.5rem;
  border-radius: 50px;
  text-decoration: none;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 0.5rem;
  transition: all 0.3s ease;
}

.social-link:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow);
  background: var(--accent);
  color: white;
}

/* ===== SECTIONS ===== */
section {
  margin-bottom: 4rem;
}

.section-title {
  font-size: 2.5rem;
  margin-bottom: 2rem;
  text-align: center;
  background: var(--gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ===== GLASS CARDS ===== */
.glass-card {
  background: var(--glass-bg);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-radius: 20px;
  border: 1px solid var(--glass-border);
  padding: 2rem;
  margin-bottom: 1.5rem;
  box-shadow: var(--shadow);
  transition: all 0.3s ease;
}

.glass-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 12px 40px 0 rgba(31, 38, 135, 0.2);
}

/* ===== EDUCATION STATS ===== */
.education-stats {
  display: flex;
  justify-content: space-around;
  margin-top: 2rem;
  flex-wrap: wrap;
  gap: 1rem;
}

.stat-item {
  text-align: center;
}

.stat-number {
  font-size: 2.5rem;
  font-weight: 700;
  background: var(--gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.stat-label {
  color: var(--text-secondary);
  font-size: 0.9rem;
}

/* ===== PUBLICATIONS ===== */
.publication-item {
  margin-bottom: 1.5rem;
}

.publication-item h4 {
  color: var(--text-primary);
  margin-bottom: 0.5rem;
  line-height: 1.6;
}

.publication-meta {
  color: var(--text-secondary);
  font-size: 0.9rem;
  font-style: italic;
}

.doi-link {
  color: var(--accent);
  text-decoration: none;
  font-weight: 500;
}

.doi-link:hover {
  text-decoration: underline;
}

/* ===== TIMELINE ===== */
.timeline {
  position: relative;
  padding-left: 2rem;
}

.timeline::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  height: 100%;
  width: 2px;
  background: var(--accent);
}

.timeline-item {
  position: relative;
  margin-bottom: 2rem;
  padding-left: 2rem;
}

.timeline-item::before {
  content: "";
  position: absolute;
  left: -2.5rem;
  top: 0;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--accent);
  border: 3px solid var(--bg-primary);
}

.timeline-item h3 {
  color: var(--text-primary);
  margin-bottom: 0.5rem;
}

.timeline-date {
  color: var(--accent);
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.timeline-content {
  color: var(--text-secondary);
}

/* ===== SKILLS GRID ===== */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1.5rem;
}

.skill-category h3 {
  color: var(--accent);
  margin-bottom: 1rem;
}

.skill-list {
  list-style: none;
}

.skill-list li {
  padding: 0.5rem 0;
  color: var(--text-secondary);
  position: relative;
  padding-left: 1.5rem;
}

.skill-list li::before {
  content: "▹";
  position: absolute;
  left: 0;
  color: var(--accent);
}

/* ===== AWARDS GRID ===== */
.awards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 1.5rem;
}

.award-item {
  display: flex;
  gap: 1rem;
  align-items: start;
}

.award-icon {
  font-size: 2rem;
  flex-shrink: 0;
}

.award-info h4 {
  color: var(--text-primary);
  margin-bottom: 0.25rem;
}

.award-date {
  color: var(--accent);
  font-size: 0.9rem;
  font-weight: 600;
}

/* ===== CONTACT ===== */
.contact-info {
  text-align: center;
  font-size: 1.2rem;
}

.contact-info a {
  color: var(--accent);
  text-decoration: none;
  font-weight: 600;
}

.contact-info a:hover {
  text-decoration: underline;
}

/* ===== FOOTER ===== */
footer {
  text-align: center;
  padding: 2rem;
  color: var(--text-secondary);
  border-top: 1px solid var(--glass-border);
}

/* ===== RESPONSIVE ===== */
@media (max-width: 768px) {
  .nav-links {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    flex-direction: column;
    padding: 1rem;
    border-bottom: 1px solid var(--glass-border);
  }

  .nav-links.active {
    display: flex;
  }

  .mobile-menu-btn {
    display: block;
  }

  .hero h1 {
    font-size: 2rem;
  }

  .hero .subtitle {
    font-size: 1.2rem;
  }

  .skills-grid,
  .awards-grid {
    grid-template-columns: 1fr;
  }

  .social-links {
    flex-direction: column;
  }

  .container {
    padding: 5rem 1rem 1rem;
  }

  .hero-content {
    padding: 2rem;
  }
}

/* ===== THEME TOGGLE ICON COLOR ===== */
.theme-toggle i {
  color: var(--text-primary);
}

/* ===== EXPERIENCE TABS ===== */
.experience-tabs {
  display: flex;
  justify-content: center;
  gap: 1rem;
  margin-bottom: 2rem;
  flex-wrap: wrap;
}

.tab-btn {
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  padding: 0.75rem 1.5rem;
  border-radius: 50px;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--text-primary);
  font-family: "Inter", sans-serif;
  font-size: 1rem;
  font-weight: 500;
  transition: all 0.3s ease;
}

.tab-btn i {
  font-size: 1.2rem;
}

.tab-btn:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow);
}

.tab-btn.active {
  background: var(--accent);
  color: white;
  border-color: var(--accent);
}

.tab-content {
  display: none;
}

.tab-content.active {
  display: block;
  animation: fadeInUp 0.5s ease;
}